Compass



March 4, 1941. w w STANFLD 2,233,990

COMPASS Filed May?, 1940 ZSheets-Shee't 2 In ventor Patented Mar. 4, 1941 UNITED STATES PATENT OFFICE COMPASS William W. Stanfield, Largo, Fla.

Application May 7, 1940, Serial No. 333,819

2 Claims.

This invention relates to improvements in draftsmans tools, and particularly to improvements in Compasses, with more particular reference to such compasses as are known as beams compasses.

' An object `of the present invention is to provide a compass that is particularly equipped for use in designing ovals and accordingly is adaptable to the needs of al1 classes of craftsmen, especially such as are engaged in the designing of "neon and various other types of signs.

A further object of the invention is to provide a compass of this character characterized by simplicity of construction and use and which will have a wide range of usefulness rendering it adaptable to various kinds and sizes of work.

The invention together with its objects and` advantages will be best understood from a study of the following description taken in connection with the accompanyingdrawings wherein:

Figure 1 is a perspective view illustrating a preferred form of the invention.

Figure 2 is a. perspective view of an extension marker bar.

Figure 3 is a perspective view of a pair of rods forming part of the invention. 4

Figure 4 is a detail sectional view taken substantially on the line --Il of Figure l.

Figure 5 is a perspective viewq illustrating a I0 modified form of the invention.

Figure 6 is a plan view illustrating the use o f the form of the invention shown -in Figure 5 in scribing an oval.

Figure 7 is a perspective view of a holder for a marking instrument, and

Figure 8 is a perspective view ofv a third pair of rods to be used in accordance with the presentinvention.

Referring in detail to the drawings, and particularly to the form of the invention shown in Figures 1, 2 and 4, it will be seen that in this form of the invention the compass comprises an extension frame embodying a. pair of relatively fiat oblong bars or plates 5-5, each of` which is provided at one end thereof with a head 6 that extends upwardly from its bar 5 and terminates in thereof the plates 5 and whichi is provided with slots I0 coacting with threaded openings II to accommodate screws or other fastening elements through the medium of which thev plates 5 at the desired position of adjustment relative to one 5 another and to the channel member 9 may be secured to the end that the frame may be secured at any desired position of extended or retracted adjustment. Thus in this connection the frame may be extended to a length as to accommodate a pair of guide rods I2`; or extended to its full length to accommodate a pair of guide bars I2a; or may be retracted to the extreme of such retraction for accommodating a pair of relatively short guide rods I2b shown in Figure 3.

Also in accordance with the present invention the channel member 9 intermediate its ends is provided with an aperture to receivel a pivot element I3 that extends through the center aperture I4 of the channel 9 and through aligned openings II in theoverlapping ends of the plates 5 for securing said plates 5 and channel member 9 in assembled position and atthe desired position of adjustment; the pivot screw I3 having a threaded terminal that threads into an opening 25 II in the lower plate 5 as shown in Figure 4. In this connection it is to be noted that the openings IIa in the overlapping plate-5 are of larger diameter than the openings II in the lappedplate 5, the openings II in the plate 5 being threaded, while the openings IIa are not threaded.

Further in accordance with the present in ven, tion there are provided a pair of coextensive ratio` bars I4 and I5.

The ratio bar I4 at one end thereof is bent laterally as at IB'and then inwardly-as at Il in parallelism with the bar I4, and the inwardly directed extremity AI'I of said bar is apertured to accommodate the pivot elementl I3 so that said ratio bar I4 is free to rotate about the pivot element I3.

The ratio bar I5 at one end thereof is similarly formed as at I8 and I9, and the extremity I9 of the ratio bar I5 is provided with a squared aperture to receive a squared shoulder 2li of a bolt 2|.

The bolt 2I extends upwardly through a slide block 22 that is provided with a pair of through openings 23 to accommodate the rods of the` pair of rods I2, or the rods of the pair of r'ods I2b, or the rods of the pair of rods I2a, depending upon 50 which pair of rods are used; the use of the selected pair of rods, being dependent, of course, lupon the desired length of therframe; it being noted in this connection that .the double-ply heads 6 of the -bars 6 have the innermost plies thereof .suitably aper- Acase may be. Y

tured to accomodate the extremities of the bars of the selected pair of bars I2, I2a, or I2b, as the Adverting again 'to the ratio bar I4, it will be seen that the same is provided with a longitudinal series of threaded openings 24 with which align the openings of aseries of openings 25 in the ratio bar I5, and these ratio bars I4 andv I5 are pivotally connected together at the desired point in the length of the respective bars through the medium of a pivot element 28, the extremity of the shank of which is threaded to threadedly engage in a selected opening 24.

with the bolt 2l through the medium of a nut 29 threaded on the extreme upper end of the bolt 2I-. -1

The' marker bar 28 is graduated as at 28, and the ratio bar I5 is graduated as at 29a, the graduations being in terms of inches and fractions thereof.

Also, in accordance with the present invention there is provided a Aholder for a marking in- .strument such as s hown in Figure 1 and indicated by the reference numeral 3G.

The holder shown inFigure 1 and indicated by the reference numeral 3| is in the form of a split sleeve which, at the edges thereof formed by the split, is provided with .apertured extensions 32 to which is pivoted a lever 33 that when swung downwardly to the position shown in Figure 1 tends to cause the sleeve to contract about the marking element 3010i holding the latter securely within the sleeve of the holder 3|. At the upper end thereof the holder 3| is provided with a spring clip 34 that engagesV the marker bar 29 as shown in Figure 1 so as to permit the holdto be easily slid longitudinally of the er 3I markerbar to the desired position of adjustment thereon.

For accommodating a larger marking instruer shown .at 35 embodies a pair of spring-biased,

hinged clamping jaws- 38 and a channel-shaped suspension element 31, the latter adapted to accommodate in the channel thereof the marking bar 28 in a manner to suspend the holder from the marking bar .and to permit the holder to be readily positionedA at .the desired, position of adjustment on the marking bar.

To use the device in scribingeither a circle or an oval, and after the-parts have been assembled, the device is positioned on the drawing paper or the like so that the pivot element I3 will be at the center of the ligure to be scribed. When this positioning has been accomplished the parts are so positioned that the bolt 2I will be directly in vertical alignment with the pivot element I3.

Depending uponthe dia-meter of the oval orcircle to be scribed, the marker 30 is positioned at the desired and proper position on the marker bar 29 and the screw 28 is set opposite the proper. f A graduation on the ratio bar I5 for .pivotally connecting said bar I5 and bar I4. I

The operator then moves the marker bar 28 to the right or left as the case may be,I the ratio bar I4 swinging about the pivot element I3 and the ratio bar I5 swingingabout the screw 28 as a pivot permitting the marker bar 28, always in alignment with the ratio bar I5, to move as required for a complete scribing of the circle or oval as the case may be.

Further in accordance with the present invention, and to prevent retrograde movement of the ratio bar I4 there is pivoted on the part I8 of said bara double-acting dog 38 cooperable with a circular series of apertures 39 provided on the channel member 9 circumjacentthe opening provided therein for accommodating the pivot element I3.

Also 4in accordance with the present invention there is provided for use as an extension of the marker bar 28 an extension marker bar 28a.

For detachably connecting the marker bar exf y tension 28a with the'marker bar 28 the latter at its free extremity is provided with an upstanding projection 40 to be engaged in a selected opening 4I provided in relatively spaced rela- In the form of the invention shown in Figure 5, l

the invention comprises a frame 5a in the form of an loblongphannel block in the channel ofv which is fitted a channel rail 44, the channel bar 5a being formed of a plurality, in the present instance 3 complemental and aligning sections, and the channelrail 44 being also composed of a plurality, in the present instance 3, channel rail sections, one of the sections being of greater length than either of the two remaining sections so that said one section will overlap the joints between the sections of the frame 5a when th three sections of the frame are used. 1

Thus by eliminating any one or more of the sections thereof the frame 5a may be decreased in length, and of course only the required number of sections ofthe rail 44 will be used with the increased or decreased length of the frame Slidable in the channel rail is a block 45 which corresponds with the slide block 22, hereinbefore described.

However, in this form ofthe invention the marker bar, indicated by the reference numeral 48 and the ratio bar I5a corresponding to the hereinbefore described ratio bar I5, are integral one with another and at the junction of the bars 46 and I 5a the same are pivoted to the block 45 as at 41.

Also in accordance with this invention there is provided a ratio bar I4a, corresponding to the hereinbeiore described ratio bar I4, and this -ratio bar -I4a is pivoted to the frame 5a intermediate the ends of the frame, regardless ofr the length of the frame, as at 48.

vRatio bars I4a and I5a are each provided with avlongitudinal series of apertures, the apertures in the bar, I 4a being threaded to 'accommodate the threaded end of a pivot screw 49 corresponding to and functioning in substantially the same manner as the pivot screw 28. Thus it will Abe y seen that the pivotal connection between the @ratio bars I4a and I5a may be adjusted as found Also in accordance with the use of this inverntion there will be provided for sliding engagement with the marker bar 4U a marker holder 3| or 35 as found desirable for carrying the usual marker 30. A

In Figure 5 is illustrated the manner of usin this form of device for drawing arcuate lines of such magnitude as would be diflicult with other compass means in confined spaces, while in Figure 6 is illustrated the manner of using such form of device for drawing an oval.

It will also be appreciated that by reason of an opening Il adjacent one end of the frame 5,

and simply by swinging the endI of the base frame around after the i'lrst half ofthe oval has been drawn, and leaving the pivot I3 in the same .relative position.

It will also be understood that in order to make possible the drawing of ovals in a direction opposite to that shown in Figure 5, marker bar 46 may be positioned to extend in a. direction opposite to that shown in. Figure 5 by engaging the pivot 41 in the slide 45 with a selected Aopening in the ratio bar la and of course making the necessary vadjustment in the pivotal connection between the ratio bars I5a and lla.'

Further in connection with the use of the holders 3l and 35 for a marking element, it is to be f understood that these holders may be so constructed as to permit the marking element to extend above and below the marking bar.

It is thought'that a clear understanding of the construction, manner of assembly, uses, and many advantages of a compass o! this character .wm 6e had without a more aeianedtdescripnon; but in this connection it may be explained that to my knowledge prior art devices in this class have been confined as to construction, utility, etc., to needs within the scope of the drafting board, whereas I, having knowledge of the more' extensive needs and uses of a compass, especially by designers of large work, have endeavored to provide an adjustable construction of compass which can be easily manipulated and can be used with facility in designing work from close to its narrow base -to an extensive magnitude far greater than the capacity of known prior art devices have permitted.

It is also to be understood that while I have herein shown and described a preferred embodiment of the invention, it is not intended to restrict the invention to the precise details herein shown and described, other than as may be required by the state of the priorart and scope of the appended claims.

Having thus described the inve claimed as new is:

1. In a draftsmans compass, an' elongated frame, a rod extending parallel to the frame and supported in an upper position thereon, a block slidably supported by the rod, a pin passing vertically through the block and supported for rotion what is tary movement therein, a pair of ratio bars each .having e hooked end, the hook of one bar extending downwardly, a pivot pin passing through the hook -of this bar into the frame, the hook of the other bar extending upwardly and fastened to the lower end of the pin in. the block, a pivot pin for pivoting the Aouter portions of the two bars together, means for adjusting the pin last mentioned longitudinally of the bars and amarkried by the block' forming an extension of the ratio bar which is connected with the block.

2. In a draftsman's compass, `a base,` 'a ratio bar having one end of U-shape to provide a long er bar fastened to the upper end of the pin car- I is adapted to receive the dog f or holding the bar against. movement in one direction.

WILLIAM vW-. STANFIELD. 

